It turns out ap_verify was using --clobber-partial-outputs, which was renamed to --clobber-outputs on DM-30649 to reflect its new, more general behavior.

I had thought --clobber-partial-outputs was only really useful for contexts in which preemption and automatic retries were in play, so I'm somewhat curious what it was needed for here, but switching to the new argument is trivial and that's my plan.